Description

Submission

class Solution {
public:
    vector<vector<string>> displayTable(vector<vector<string>>& orders) {
        map<int, unordered_map<string, int>> table;
        set<string> foods;

        for(auto& order: orders) {
            int tid = stoi(order[1]);
            string food = order[2];
            table[tid][food]++;
            foods.insert(food);
        }

        vector<vector<string>> rets;
        rets.push_back({"Table"});
        copy(foods.begin(), foods.end(), back_inserter(rets[0]));
        for(auto [tid, f]: table) {
            vector<string> cur;
            cur.push_back(to_string(tid));
            for(auto food: foods) {
                cur.push_back(to_string(f[food]));
            }
            rets.push_back(cur);
        }

        return rets;
    }
};